Treatment compositions, such as fabric softeners, typically comprise benefit agents such as silicones, fabric softener actives, perfumes and perfume microcapsules. Benefit agents, in particular particulate benefit agents, can cause creaming which is a form of instability. Polymers have been used to decrease creaming. Unfortunately, polymers introduce depletion flocculation which results in a water rich layer at the bottom of the treatment composition. Thus, one form of instability is traded for another form. Such water rich layer decreases benefit agent dosage uniformity and has an undesirable appearance.
Applicants recognized that the traditional polymer architecture was the source of the stability and benefit agent dosage problems as such architecture does not include anionic monomers. Applicants discovered that, for fabric softeners, in particular low pH fabric softeners, the judicious selection of the anionic monomer level in a predominantly cationic cross-linked polymer and the cross-linking level of such polymer results in a stable treatment composition with improved deposition of benefit agents. While not being bound by theory, Applicants believe that the proper selection of such materials yields a stable colloidal glass comprised of cross-linked polymers that generally cannot entangle and that provide a weak anionic interaction that drives benefit agent deposition without causing aggregation. Thus, fabric treatment compositions comprising such particles have a surprising combination of stability and deposition efficiency. Such treatment compositions provide benefits that such as improved fabric hand (including fabric feel), antistatic, and freshness.